Ruthenium nanoparticles supported over mesoporous TiO<sub>2</sub> as an efficient bifunctional nanocatalyst for esterification of biomass-derived levulinic acid and transfer-hydrogenation reactions
作者:Usha Mandi、Noor Salam、Sudipta K. Kundu、Asim Bhaumik、Sk. Manirul Islam
DOI:10.1039/c6ra10233f
日期:——
characterize the Ru@MTiO2 material. This nanostructured ruthenium supported over a TiO2 material exhibited excellent bifunctional catalytic activity in the esterification of levulinic acid and selective transfer hydrogenation reactions of nitroarenes under mild reaction conditions. This Ru@MTiO2 catalyst can be easily recovered from the reaction mixtures and reused five times without a significant loss
Cascade Reductive Etherification of Bioderived Aldehydes over Zr-Based Catalysts
作者:Suhas Shinde、Chandrashekhar Rode
DOI:10.1002/cssc.201701275
日期:2017.10.23
value‐added ethers from bioderived aldehydes. Etherification of 5‐(hydroxymethyl)furfural with different aliphatic alcohols over acidic Zr–montmorillonite (Zr‐Mont) catalyst produced a mixture of 5‐(alkoxymethyl)furfural and 2‐(dialkoxymethyl)‐5‐(alkoxymethyl)furan. The latter was selectively converted back into 5‐(alkoxymethyl)furfural by treating it with water over the same catalyst. The synthesis of 2
In Situ Generated Catalyst System to Convert Biomass-Derived Levulinic Acid to γ-Valerolactone
作者:Xing Tang、Xianhai Zeng、Zheng Li、Weifeng Li、Yetao Jiang、Lei Hu、Shijie Liu、Yong Sun、Lu Lin
DOI:10.1002/cctc.201500115
日期:2015.4.20
2 μmol g−1 min−1 were achieved in 2‐butanol at 240 °C in 2 h. The in situgenerated ZrO(OH)2 was characterized comprehensively and its unexpected catalytic efficiency was attributed mainly to its extremely high surface area. A crude LA stream from the acid hydrolysis of cellulose was extracted into 2‐butanol and subjected to this catalystsystem to give a GVL yield of 82.0 % even in the presence of humins
这是(OH)的HCl /的ZrO的第一份报告2点的催化剂在原位的ZrOCl的自主分解制备2 ⋅ 8 H 2,其催化LA的酯化串联带O中乙酰丙酸(LA)/ 2-丁醇溶液,在不使用外部H 2的情况下,通过Meerwein–Ponndorf–Verley(MPV)还原将水环化为γ-戊内酯(GVL)。在240°C下2小时内在2-丁醇中,纯净LA的最大GVL产率为92.4%,GVL形成速率为1092.2μmolg -1 min -1。原位生成ZrO(OH)2进行了全面表征,其出乎意料的催化效率主要归因于其极高的表面积。来自纤维素酸水解的粗制LA物流被萃取到2-丁醇中,并经过此催化剂体系的处理,即使在腐殖质的存在下,GVL收率仍为82.0%。
Conversion of levulinic acid to γ-valerolactone over Zr-containing metal-organic frameworks: Evidencing the role of Lewis and Brønsted acid sites
作者:J.M. Guarinos、F.G. Cirujano、A. Rapeyko、F.X. Llabrés i Xamena
DOI:10.1016/j.mcat.2021.111925
日期:2021.10
multistep complex reaction evidences the participation of the different acidsites (Lewis or Brønsted) of the material in each individual step: Brønsted-induced acidsites catalyze esterification reaction efficiently, while Lewisacidsites are the preferred sites for the MPV step. Sulfation of MOF-808 is used to enhance the Brønsted acidity of MOF-808, which improves the performance for esterification
评估了含 Zr 的 UiO-66 和 MOF-808 通过各种途径将乙酰丙酸 (LA) 转化为 γ-戊内酯 (GVL):(i) LA 逐步酯化为乙酰丙酸正丁酯 ( n BuL) 和 Meerwein -Ponndorf-Verley (MPV) 减少到 GVL;(ii) 用正丁醇进行一锅两步酯化,然后用秒进行 MPV 还原-丁醇;(iii) 通过串联反应将 LA 直接转化为 GVL。这种多步复杂反应的选择证明了材料的不同酸位(刘易斯或布朗斯台德)在每个单独步骤中的参与:布朗斯台德诱导的酸位有效地催化酯化反应,而路易斯酸位是 MPV 步骤的首选位点。MOF-808 的硫酸化用于增强 MOF-808 的布朗斯台德酸度,从而提高酯化性能。然而,引入的硫酸根基团对 MPV 步骤是有害的,因为它们减少了可用于形成所需的庞大过渡态的孔隙内空间。这些结果证明需要在 Brønsted 和 Lewis 酸位
Eco-Friendly Natural Clay: Montmorillonite Modified with Nickel or Ruthenium as an Effective Catalyst in Gamma-Valerolactone Synthesis
influence of solvents on the studied reaction was also performed—protic alcohol-based solvents caused the formation of levulinic and valeric acid esters in the reaction mixture. The selectivity was influenced mainly by the alcohol structure (the highest selectivity obtained using isopropyl alcohol and sec-butanol). Mainly the solvent’s donor number (except ethanol) influenced the reaction rate. The prepared